1. Field of the Invention
This invention relates to a stud for snowmobiles and the like and more particularly to a stud having a shank integrally mounting a new and improved head thereon.
2. Description of the Prior Art and Objects
Studs for snowmobile tracks have been provided heretofore such as that illustrated in U.S. Pat. No. 4,758,055 issued to Jay Anderson on Jul. 19, 1988. Such studs include shanks which pass through apertures in a resilient snowmobile belt and planar heads which, when mounted on the belt, so as to be tightly clamped thereto, radially outwardly displace a portion of the resilient belt to provide a bulge adjacent the leading and trailing edges of the head. The endless track is typically mounted for movement in endless path about a snowmobile drive wheel and an idler wheel. As the track negotiates the wheels, the bulges, when negotiating the wheels tend to induce vibration. Accordingly, it is an object of the present invention to provide a new and novel stud which will reduce vibration in a snowmobile track.
It is another object of the present invention to provide a new and novel stud which will reduce the bulging which previously occurred in snowmobile drive belts adjacent the leading and trailing edges of the head of the stud when the stud is installed in the track.
One type of stud is mounted to a snowmobile track with a nut which is threadedly mounted thereon. As the nut is threaded onto the stud, the head of the stud is axially moved in a direction toward the inside surface of the track until it is embedded in the resilient track material to a depth that the axial end surface of the stud head is flush with the inside track surface. When the stud is installed, the head will axially displace a portion of the resilient track material. The studs are more rigid if a portion of the resilient track, which has been axially displaced by the head along the shank of the stud, is also radially inwardly displaced toward the shank. Accordingly, it is another object of the present invention to provide a snowmobile stud having a cup shaped perimetrically extending flange for radially inwardly urging a portion of the track adjacent the shank radially inwardly towards the shank.
Yet another object of the present invention is to provide a stud of the type described including a shank having an elongate axis and an integral transverse head having a concave-axially inner surface for radially inwardly urging a portion of the track adjacent the stud shank when the stud is mounted on the track.
It is another object of the present invention to provide a stud for a snowmobile track which, for a track of a predetermined thickness, will increase the total bearing surface area between the track and the shank of the stud.
Another object of the present invention is to provide a stud including a head which will displace a portion of the track material along the length of the shank to provide increased stability to the stud.
As the flat planar head of the prior art stud engages and negotiates the snowmobile drive wheels, the contour of flat head surface will not match the arcuate contour of the snowmobile wheels and thus substantial forces are introduced to the head tending to bend and break the stud head. Also, the flat or planar stud head, as it negotiates the snowmobile drive wheels, tends to push or lift the stud and the track away from the wheels. This increases the tension on the track and tends to stretch the track. Such stretching is undesirable and detracts from track life. Accordingly, it is another object of the present invention to provide a new and novel stud which will improve snowmobile track life.
Yet another object of the present invention is to provide a new and novel snowmobile stud which will decrease the stretching of the snowmobile track.
Still another object of the present invention is to provide a snowmobile stud having a head with a curved wheel engaging axial end surface.
Yet another object of the present invention is to provide a snowmobile stud including an integral mounting head including a snowmobile wheel engaging arcuate portion having a radius of curvature equal to the radius of the snowmobile drive wheel.
Typically, snowmobiles include a suspension system having nylon strips bearing against the inside or upper surface of the lower run of an endless snowmobile belt. Some of the stud heads will bear against the undersides of these nylon strips as the belt moves in its endless path of travel. As the prior art planar stud head negotiates the undersides of the nylon strips, substantially the entire axial end surface of the planar head frictionally engages and wears on the undersides of the confronting strip. In snowmobile racing machines, the energy dissipation resulting from this friction can be significant. Accordingly, it is another object of the present invention to provide a new and improved snowmobile ice stud which will reduce the friction between the endlessly moving snowmobile ice stud and the snow machine.
Another object of the present invention is to provide a snowmobile ice stud which will decrease the energy required to propel a snowmobile.
Yet another object of the present invention is to provide a stud for snowmobiles and the like having a head with a central portion, a radially outer terminal flange portion, an intermediate portion integrally formed with and disposed between the central portion and the terminal flange portion with the central portion and terminal flange portions being axially inwardly recessed relative to the intermediate portion.
Snowmobile racers sometimes introduce lubricant between the track and the nylon or plastic snow machine suspension runners or nylon strips to reduce friction therebetween. It has been found difficult to uniformally disperse lubricant along the bearing surfaces with which the track engages and thus this tends to introduce track wear and increase the energy required to propel the snowmobile. It has been found, according to the present invention, that by providing a central recess in the axially outer, centrally disposed surface of the head of a snowmobile stud, that the recess will form a lubricant receiving cavity for receiving lubricant and dispersing lubricant along the length of the snowmobile wear strip. Accordingly, it is another object of the present invention to provide a snowmobile ice stud which includes a head having a central recess in the outer surface thereof for receiving and distributing lubricant along a portion of a snowmobile wear surface.
Another object of the present invention is to provide the combination of a snowmobile track and a new and novel stud of the type disclosed herein.
Other objects and advantages of the present invention will become apparent to those of ordinary skill in the art as the description thereof proceeds.